A. Yes. You should turn on the Windows XP Internet Connection Firewall for all computers in your home network. This helps prevent the spread of viruses or worms across your network if a computer is infected. A computer on the network could become infected through a separate Internet connection, such as one on a laptop that is used on your home network and on public networks. Or a virus could be introduced to a computer on your network by way of e-mail or software installed from a CD or floppy disk.